Turbojet engines (including turbofan engines), ramjet engines and scramjet engines are known as jet engines for flying bodies flying faster than the speed of sound. These are jet engines which take air to operate and the speed of the taken air strongly depends on the flying speed, especially with respect to a ramjet engine and a scramjet engine.
As a flame stabilizing mechanism for holding a fuel-burning flame of a jet engine, use of a boundary layer generated on a wall surface of the combustor or a low-velocity region existing near a flame stabilizer disposed on the wall surface of the combustor is known in the art. To stabilize a flame with these approaches, it is necessary to distributedly supply fuel toward a proper region near the wall surface of the combustor (which may be also referred to as “flame holdable region”, hereinafter).
FIG. 1 is a schematic section view schematically illustrating the structure of a jet engine. The jet engine 102 includes a body 110 and a cowl 140 disposed under the body 110 to form a space 150 through which gas is allowed to flow. The front lower part of the body 110 and the front part of the cowl 140 form an inlet 111 which introduces air into the space 150. The middle lower part of the body 110 and the middle part of the cowl 140 form a combustor 112 which mixes fuel and air to burn. The rear lower part of the body 110 and the rear part of the cowl 140 form a nozzle 113 which expands and exhausts the burnt gas. The combustor 112 includes fuel injectors 120. The fuel injectors 120 are disposed on a wall surface 121 corresponding to the combustor 112 of the lower part of the body 110. The combustor 112 may include a flame stabilizer (not shown) disposed on the wall surface 121 backward from the fuel injectors 120. The fuel injectors 120 inject fuel G into the space 150. The jet engine 102 mixes the air taken from the inlet 111 and the fuel G injected from the fuel injectors 120 to burn the fuel G and exhausts the burnt gas backward of the body 110 with the burnt gas expanded with the nozzle 113. As to the flame stabilization in the combustor 112, a part of the fuel G is diffused and supplied to a low-velocity region existing in the boundary layer generated on the wall surface 121 of the combustor 112, to stabilize the flame. When a flame stabilizer is disposed on the wall surface 121 of the combustor 112, apart of the fuel G is diffused and fed to a low-velocity region existing near the flame stabilizer, to stabilize the flame.
As a related art, Japanese Patent Application Publication No. 2012-202226 discloses a jet engine. The disclosed jet engine includes an air compressing section, a fuel injection section and a combustion section. The air compression section compresses air to generate compressed air. The fuel injection section injects fuel into the compressed air. The fuel is burnt in the combustion section. The fuel injection section includes an injection angle control section which changes the direction of a first injection orifice through which the fuel is injected.